You can set blockUI to work for all functions on the page by adding to a global jQuery event handler. To make sure it doesn't get called on autocomplete ajax calls we have to determine if the call is an autocomplete call or not. The problem is that these global functions don't have that much information available to them. However ajaxSend does get some information. It gets the settings object used to make the ajax call. the settings object has the data string being sent. Therefore what you can do is append to every data string in every ajax request on your page something like:
¬autocomplete=notautocomplete
For example:
$.ajax({data:"bar=1&foo=2¬autocomplete=notautocomplete"})
Then we can put this code in your document ready section before anything else:
$(document).ajaxSend(
function (event, xhr, ajaxOptions){
if(ajaxOptions.data.indexOf("notautocomplete") !== -1){
$.blockUI;
}
});
$(document).ajaxStop($.unblockUI);
Of course the other better idea would be to look for something unique in the auto complete requests, like the url, but that depends on which autocomplete plug-in you are using and how you are using it.